Characterization by Photoluminescence and Raman Spectroscopy of the Oxide Scales Grown on the PM2000 at High Temperatures

Abstract

The microstructural change of a thermal oxidation on a PM2000 superalloy was investigated after a 48 h isothermal heat-treatment. The oxides (transitions aluminas, [Formula: see text]-alumina and mixed oxides) were characterized using the Raman spectroscopy, the Photoluminescence (PL) spectroscopy, MEB observations and the X-ray diffraction for temperatures between 600°C and 1200°C. The X-ray diffraction results under conventional incidence conditions make it possible to estimate the crystallites size and the specific surfaces of the [Formula: see text]-alumina. The PL analyses at various excitation wavelengths (200[Formula: see text]nm, 234[Formula: see text]nm, 326[Formula: see text]nm and 532[Formula: see text]nm) provide important information on the existing defects (intrinsic and extrinsic) according to the oxidation temperature. The Raman spectroscopy ([Formula: see text].18[Formula: see text]nm) gives the various signatures of the various alumina generated ([Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text]-Al2O3).